adverbtowards the past time.中文就叫副词,来指回到过去,回忆的意思。back很广泛,有这些用法,是我词典点找到的,不明白可以追问:)2back adverbDefinition of BACK1a : to, toward, or at the rearb : in or into the ...
back此处作副词,意思是“向后”、“后退地”。类似的句子有Many people in the cities even didn't have enough food for the meals back in early 1970's.
其实没有back这类句子语法上也没有任何问题,加上只是用来强调事情发生的时间已经不是最近了。...